1. Field of the Invention
The present invention relates to a fan rotor blade of an aircraft jet engine which is configured to take external air into an engine case by rotating integrally with a fan disk.
2. Description of the Related Art
As light-weight and high-strength materials, composite materials (FRP: fiber reinforced plastics) formed from a resin (thermosetting resin or thermoplastic resin) and fibers have attracted attention in the field of aircraft jet engines in recent years. A wide variety of fan rotor blades using such composite materials have been developed and come into practical use.
Meanwhile, a foreign object such as a bird and ice entering an engine case may collide with fans placed in the forefront of an aircraft jet engine. In preparation for such a collision of a foreign object, fan rotor blades made from the composite materials are equipped with measures to secure sufficient impact resistance.
In a fan rotor blade disclosed in Japanese Patent Application Laid-Open Publication No. 08-210102 (PTL 1), a blade body is formed from a composite material, and a metal sheath is provided at a portion on a leading edge side as well as a tip end side of a blade body which is most prone to a collision of a foreign object. Here, the metal sheath has higher strength than that of the composite material. Thus, PTL1 aims at a reduction in the overall weight of the fan rotor blade, and concurrently a reduction in damage caused by the collision of the foreign object by forming the blade body from the composite material, and providing the part of the blade body with the metal sheath.